story = "Once upon a time, in a land far away lived a brave knight named Arthur."
#1.统计故事单词数量
story_1 = story.split(" ")
print(story_1)
count = len(story_1)
print(count)
#2.替换主角名
print(story.find("Arthur"))
story_1 = story.replace("Arthur", "Zhaojiayi")
print(story_1)
#3.故事改为大写
print(story.upper())
#4.故事改为小写
print(story.lower())
